"If we attack the metro [subway system in Barcelona], the emergency services can't get there," one of the suspected suicide bombers told the informant, El Pais reported on Saturday. "Our preference is public transport, especially the metro."

El Pais reported that it had access to the informant's testimony to Spanish officials.

CNN has confirmed that authorities have given high importance to an informant's testimony.

The judge who ordered 10 suspects held for allegedly plotting a suicide attack in Barcelona, cited in his rulings the testimony of an informant. CNN has viewed the rulings.

Spain's Interior Minister last Friday said an informant warned of a planned suicide attack against Barcelona's metro on the weekend of January 18 to 20. But he added that, for now, "there is only the testimony of an informant" regarding the timing.

Spain's attorney general, Candido Conde-Pumpido, said last week that the cell could have contained six suicide bombers, two explosives experts and two ideologues.

Judge Ismael Moreno, in rulings last Wednesday, wrote that the informant had named three suspected suicide bombers and an explosives expert, all of whom had traveled from Pakistan to Barcelona since last summer. The judge ordered these four men held, out the total of 10 jailed suspects who are from South Asia.

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They include nine Pakistani nationals and a man from India, who is Muslim.

A court-appointed translator told CNN that all 10 suspects testified during their arraignments that they were innocent.

The cell planned three attacks in Spain, one in Germany and others in France, Britain and Portugal, according to the informant, El Pais reported.

On Sunday, another El Pais story added that the "wave of attacks" was to have been carried out by the Barcelona group and other extremist Pakistani cells were to attack elsewhere in Europe.

The informant told authorities about potential links between the Barcelona group and suspected extremists in other countries, the interior minister said Friday.

The informant had traveled by train from France to Barcelona on January 16, a few days before police made arrests in Barcelona, El Pais reported Saturday. A day earlier, the newspaper reported that the informant worked for French intelligence.

Al Qaeda was planning to take responsibility for the first attack in Barcelona through Baitullah Mehsud, a Taliban commander whom the Pakistani government blames for last month's assassination of opposition leader Benazir Bhutto, El Pais reported.

"Only the leadership of the organization knows what requests the emir (Baitullah) will make after the first attack, but if they are not carried out, there will be a second attack in Spain, and a third," a cell leader told the informant, El Pais reported. "And then in Germany, France, Portugal and the United Kingdom. There are many people prepared there."

In Barcelona, two pairs of suicide bombers were to attack in separate metro stations, the paper said, citing the informant's testimony. One of the cell leaders said the bombs were supposed to be hidden in backpacks or bags and that other cell members were to detonate them by remote control, the paper added.

Two other pairs of suicide bombers were to strike elsewhere in Spain, while another suicide bomber was to attack in Germany, although the informant said he did not know where or when those attacks were to occur, El Pais reported.

Three other terrorists were assigned to attack in France and two in Portugal, El Pais reported, although it did not mention locations or times for those attacks either.

Civil Guards initially detained 14 people in Barcelona, but released two before arraignments last Wednesday. The judge then released two more, leaving 10 in jail for further investigation. It was not immediately known if the alleged informant may have been among those arrested and released.

"This cell was preparing to attack," Interior Minister Alfredo Perez Rubalcaba said Friday in an interview with Spanish radio network SER. "It's clear they were going to try, whether last weekend (January 18 to 20) or within 15 days."

But he said police have not found explosives "in sufficient quantity" to have carried out the assault.

"We have found a modest quantity of explosives," Rubalcaba said, adding that they may have been intended for use in training the suspects.

The judge in his rulings wrote that the group "had achieved human operational capacity and were very close to achieving full technical capacity with explosives, with the aim of using those explosives for a jihadi terrorist attack."

Rubalcaba said that, for any such suspected terrorist cell, "the time from getting explosives to carrying out the attack can be very short."

The judge wrote that police had found nitrocellulose and mechanical and electrical elements that could have been used to make one or more bombs.

More than 300 suspected Islamic extremists have been arrested in Spain since the Madrid train bombings killed 191 people and wounded more than 1,800 on March 11, 2004, Rubalcaba said.

Last October, more than a dozen Islamic extremists were convicted in Madrid for their roles in the train bombings.

The 2004 bombings came just three days before general elections, in which Socialist Prime Minister Jose Luis Rodriguez Zapatero won an upset victory.

The latest arrests in Barcelona come less than two months before the next general elections, to be held March 9, when Zapatero seeks re-election.

Spain remains on "permanent alert" against Islamic terrorism. Al Qaeda communiques regularly make specific references to Spain.E-mail to a friend